I have a HP-41C, and it behaves strange. It turns off itself after about 20 seconds. I tried to replace the batteries, did not help. Otherwise it works OK, but if I do not touch the keyboard, even when in PRGM mode, it shuts down. Any ideas?

(01-20-2016 08:41 PM)boniholmes Wrote: I have a HP-41C, and it behaves strange. It turns off itself after about 20 seconds. I tried to replace the batteries, did not help. Otherwise it works OK, but if I do not touch the keyboard, even when in PRGM mode, it shuts down. Any ideas?

While it's likely tightening the screws will fix it, if you haven't done this before, be very careful to not over-tighten the screws either, as it's very easy to break the internal screw posts by over-torqueing the screws.

Randy taught me long ago to use a full-sized screwdriver, rather than a tiny or jeweler's screwdriver, as you have better control. Turn slowly and evenly; only do about 1/8th turn at a time, repeat if needed. You will be able to tell when you reach the end, if you are gentle and careful.

Usually, you can also notice that the case halves (top and bottom) are tighter as well; try grabbing the middle bezel/band that wraps around the middle with thumb and index finger and gently twist pushing in opposite directions, both before and after tightening - you should notice a difference if that was the problem. Good luck and let us know...

Extremely very special thanks for your help, it is useful, as usual. I checked the link by Massimo, and made a short test in the morning. I firmly pressed the "x" button after ON,
kept it, and it temporarily eliminated that "short power off" problem. I had similar results by pressing "2", "3", and R/S buttons. Also, after power ON, I FIRMLY twisted the two end of the calculator, it resulted funny chars on the display. A closer inspection is on its way.
Bon